Re: clumsiness of pcall() syntax and how we deal with it

[Paul K <paul@...>]

> It's, generally, a cathedral vs. bazaar question. I have seen on this list that pcall() is wrapped to achieve a specific exception handling semantics. But I haven't seen any tweak that would stand out as a novel and interesting way to deal with errors. Mostly everyone is wrapping it to their taste and to achieve a subset of what you can get out of the box in most modern languages.

For the sake of completeness, I just want to mention guard/finalize
proposal that even had a working patch
(http://lua-users.org/lists/lua-l/2008-02/msg00243.html) and a related
proposal on deterministic resource cleanup
(http://john.neggie.net/2009/lua/resource_finalization).

| function appendud(tab, ud)
|   tab:beginupdate() finalize tab:endupdate() end
|   ud:lock() finalize ud:unlock() end
|   for i = 1,#ud do
|     tab[#tab+1] = ud[i]
|   end
| end

| function user:addfriend(newfriend)
|   self.friends:pushback(newfriend) guard self.friends:popback() end
|   database:addfriend(self:getname(), newfriend:getname())
| end

I like this syntax and think it's a worthy alternative to try/catch.

Paul.